This is a “real” pseudo random number generator. It use a Linear Congruential Generator (LCG) to create random number between 0 and 16.
The red signal is the random number generated.
Each cycle the next number is calculated by the circuit:
V(n+1) = [ V(n) * a + b ] MOD m
Where in this circuit a= 5.17, b=2.59V, m=16.
Right side is a counter with a 4-1 selector, to generate the control pulse.
Blue pulse - generate V(n)*a + b, and save it to left top capacitor
Green pulse - load capacitor value to ADC, and reset counter, to prepare for the MOD.
Orange pulse - do MOD. Load ADC output to counter. Counter output only last 3 digits to DAC. DAC value is then compared with incoming voltage. If < 0, a signal will be sent to “down” on counter. The final result is then saved to right bottom capacitor.
